Re: [RFC PATCH] mips: BCM63XX: select CPU_SUPPORTS_32BIT_KERNEL

[Randy Dunlap]

On 11/5/21 9:44 PM, Randy Dunlap wrote:
> On 11/5/21 8:31 PM, Florian Fainelli wrote:
> > On 11/5/2021 7:58 PM, Randy Dunlap wrote:
> > > Several header files need info on CONFIG_32BIT or CONFIG_64BIT,
> > > but kconfig symbol BCM63XX does not provide that info. This leads
> > > to many build errors, e.g.:
> > >
> > >     arch/mips/include/asm/page.h:196:13: error: use of undeclared identifier 'CAC_BASE'
> > >             return x - PAGE_OFFSET + PHYS_OFFSET;
> > >     arch/mips/include/asm/mach-generic/spaces.h:91:23: note: expanded from macro 'PAGE_OFFSET'
> > >     #define PAGE_OFFSET             (CAC_BASE + PHYS_OFFSET)
> > >     arch/mips/include/asm/io.h:134:28: error: use of undeclared identifier 'CAC_BASE'
> > >             return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
> > >     arch/mips/include/asm/mach-generic/spaces.h:91:23: note: expanded from macro 'PAGE_OFFSET'
> > >     #define PAGE_OFFSET             (CAC_BASE + PHYS_OFFSET)
> > >
> > > arch/mips/include/asm/uaccess.h:82:10: error: use of undeclared identifier '__UA_LIMIT'
> > >             return (__UA_LIMIT & (addr | (addr + size) | __ua_size(size))) == 0;
> > >
> > >
> > > Fixes: e7300d04bd08 ("MIPS: BCM63xx: Add support for the Broadcom BCM63xx family of SOCs.")
> > > Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> > > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> > > Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
> > > Cc: bcm-kernel-feedback-list@xxxxxxxxxxxx
> > > Cc: linux-mips@xxxxxxxxxxxxxxx
> > > Cc: Paul Burton <paulburton@xxxxxxxxxx>
> > > Cc: Maxime Bizon <mbizon@xxxxxxxxxx>
> > > Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> > > ---
> > > Note: I did see a bunch of build errors like this one:
> > > ../arch/mips/kernel/r4k_fpu.S:217: Error: opcode not supported on this processor: mips1 (mips1) `ldc1 $f24,192($4)'
> > > but I'm hoping/guessing that this is due to not having a proper compiler
> > > for the BCM63xx target.
> > >
> > >   arch/mips/Kconfig |    1 +
> > >   1 file changed, 1 insertion(+)
> > >
> > > --- linux-next-20211105.orig/arch/mips/Kconfig
> > > +++ linux-next-20211105/arch/mips/Kconfig
> > > @@ -329,6 +329,7 @@ config BCM63XX
> > >       select SYNC_R4K
> > >       select DMA_NONCOHERENT
> > >       select IRQ_MIPS_CPU
> > > +    select CPU_SUPPORTS_32BIT_KERNEL
> >
> > That's one option, the other could be to add:
> >
> >          select SYS_HAS_CPU_BMIPS32_3300
> >          select SYS_HAS_CPU_BMIPS4350
> >          select SYS_HAS_CPU_BMIPS4380
> >
> > Which would ensure that CPU_SUPPORTS_32BIT_KERNEL is selected AFAICT. Can you try that? What config file did you use to produce that build error BTW?
>
> The .config file that is attached to this report from the kernel test robot:
> https://lore.kernel.org/all/202111051920.dcCUQ0QN-lkp@xxxxxxxxx/
>
> Yes, I'll give your suggestion a try on Saturday.

OK, that works also. I'll send a v2 with that.

However, with that kernel .config file, it does expose another
unrelated longstanding build error:

/opt/crosstool/gcc-11.1.0-nolibc/mips-linux/bin/mips-linux-ld: drivers/iio/adc/ingenic-adc.o: in function `jz4725b_adc_init_clk_div':
ingenic-adc.c:(.text.jz4725b_adc_init_clk_div+0x10): undefined reference to `clk_get_parent'
/opt/crosstool/gcc-11.1.0-nolibc/mips-linux/bin/mips-linux-ld: drivers/iio/adc/ingenic-adc.o: in function `jz4770_adc_init_clk_div':
ingenic-adc.c:(.text.jz4770_adc_init_clk_div+0x10): undefined reference to `clk_get_parent'


I prepared a patch for that on April 26, 2021, but it looks like I never sent it.
Oh, it's incomplete, not really working yet.
Any comments on how to really fix this problem?

---
From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

MIPS does not always provide clk*() interfaces and there are no
always-present stubs for them, so depending on "MIPS || COMPILE_TEST"
is not string enough to prevent build errors.

Likewise MACH_INGENIC_SOC || COMPILE_TEST is not strong enough
since if only COMPILE_TEST=y, there are still the same build errors.

Can we fix the dissonance between HAVE_CLK and COMMON_CLK?

Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
---
 drivers/iio/adc/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20210426.orig/drivers/iio/adc/Kconfig
+++ linux-next-20210426/drivers/iio/adc/Kconfig
@@ -501,7 +501,7 @@ config INA2XX_ADC
 
 config INGENIC_ADC
 	tristate "Ingenic JZ47xx SoCs ADC driver"
-	depends on MIPS || COMPILE_TEST
+	depends on MACH_INGENIC_SOC || COMPILE_TEST
 	select IIO_BUFFER
 	help
 	  Say yes here to build support for the Ingenic JZ47xx SoCs ADC unit.




thanks.
--
~Randy